Quality improvement of Indian mackerel fish ( Rastrelliger kanagurata ) stored under the frozen condition: Effect of antioxidants derived from natural sources

Abstract

Seed extract from grapes (GSE) and papaya (PSE) were evaluated for their antioxidative and antimicrobial properties to improve the frozen storage quality of Indian mackerel (Rastrelliger kanagurta). GSE contained six times higher flavonoid content and four times higher phenolic content than PSE. Similarly, higher and dose-dependent antioxidant activity was observed in GSE as compared to PSE. As exhibited by the linoleic acid model system, the inhibition of lipid oxidation was 46.43% and 67.67% for PSE and GSE, respectively. Similarly, greater effectiveness of GSE against gram-positive bacterial strains was observed compared to PSE. Compared to the control, the formation of TMA and TVB-N was reduced by 47.92%, and 42.10% in GSE-treated fish samples and 33.22% and 25.00% in PSE-treated fish samples, respectively. The present investigation revealed that GSE and PSE treatment extended the shelf life of R. kanagurta by 60 and 30 days under frozen storage, respectively. Practical applications The results indicated that using natural extracts (Grape seed and papaya seed) for treating the whole mackerel fish could improve the storage life by controlling the lipid oxidation and quality changes during the frozen storage. Quality deterioration during frozen storage of fatty fish is of major concern for both domestic as well as export markets. Currently, traders/exporters are using synthetic antioxidant and antimicrobial substances that threaten consumer health, besides resulting in the rejection of the consignments by the importing countries. The study’s findings would help fill the research gaps in this field by contributing new knowledge and paving a way to find alternate natural preservatives to keep the quality of fish.